Plants

What is the main purpose of leaves?

Photosynthesis

List the 4 functions of leaves

gas exchange, storage, protection, photosynthesis

What is the most important leaf structure

the chloroplasts

What is the purpose of the chloroplast?

It is the organelle responsible for most photosynthesis that occurs in a plant.

How do chloroplasts work?

It works by containing photopigments (chlorophyll and other stuff) that change in the presence of light and allow reactions to occur. 

How does dry air impact photosynthesis?

not enough water for the reaction to occur.

how does gravity impact photosynthesis

pushes water downward while plant is trying to bring water up. Solution is cohesion and adhesion

How does access to sunlight impact photosynthesis?

sunlight is required for photosynthesis

name 3 adaptations of specialized leaves

produce chemicals to repel herbivores and insects

specialized structure to deter herbivores (ie. spikes like cactus)

specialized for storage of water and carbohydrates

environmental adaptation to avoid freezing and repel snow (ie. pine needles)

Name 3 human uses of plants

eating

waxes

religions ceremonies

toxins and medicine

psychotropic drugs

Draw/label plant diagram

What is a stoma? + purpose

an opening in the epidermis that allows air to pass in/out of the leaf and is controlled by guard cells.

Where are most stoma located? Why?

Lower epidermis because of gravity and bacteria and bugs won’t land on it and have direct access to the plant.

What are the differences between aquatic and terrestrial plants?

mesophyll is replaced by aerenchyma

stomata are often on the upper leaf because they have access to air and animals and hazards don’t have direct access

what is aerenchyma?

loosely packed parenchyma cells with large pores.

What are the dermal tissues?

epidermis, periderm

Guard cells - structure and function

specialized epidermal cells that have chloroplasts and open and close the stoma to control gas diffusion and manage water loss. They can inflate or deflate depending on the amount of water which opens and closes the stoma.

Stoma - structure and function

an opening in the leaf that allows for water and gases to enter or exit

Trichome - structure and function

short spiky growth that increases surface area to keep the leaf cool and secrets a sticky or toxic substance as a defence mechanism. Spikes also have the ability to puncture the skin of insects or predators. Also allow plants to climb and grab surfaces (ie. beans)

Root hairs - structure and function

one cell wide hair-like projections that increase surface area for absorption.

Root cap - structure and function

dead cells pilled onto of living tissue to protect the growing root. May security a mucous-like substance to improve movement through the dirt

Endodermis - structure and function

a layer of cells between the cortex and vascular tissue of the root which splits vascular tissue and cells that need water.

Casparian strip - structure and function

a barrier like group of cells which act like one way doors to pull wanter into the plant root

Periderm - structure and function

a layer of cells that protects the plants inner tissues from stress

What are the vascular tissues

xylem and phloem

Treacheid - structure and function

dead cells that taper at the ends and overlap which transport water from the roots to the different parts of the plant. They also act as structural support. Found in gymnosperms

Vessel element - structure and function

long continuous tubes of dead, hollow cells that carry water and are found in angiosperms

What are the parts of the phloem in angiosperms?

sieve tubes, phloem parenchyma, phloem fibers and companion cells

Sieve tube - structure and function

living cells that transport nutrients and sugars

Companion cell - structure and function

move sugars in and out of phloem and manage the sugar concentration

What are the 3 types of ground tissue

parenchyma, collenchyma, sclerenchyma

Parenchyma - structure and function

flexible ground tissue which makes up the majority of plant cells. It is used for storing and/or photosynthesis

Collenchym - structure and function

elongated cells specialized for structural support

Sclerenchyma - structure and function

ground tissue found in trees that have thick cell walls with lignin which acts as a main support. (Tree bark)

Aerenchyma - structure and function

specialized parenchyma in aquatic plants and facilitates the movement of gases in and out of tissues swell as helps aquatic plants float.

What are the 3 main types of meristematic cells

apical, intercalary, lateral

Where is apical meristem found

tip of plant and roots

Where is intercalary meristem found

along the stem and base of leaves

where is lateral meristem found

new protective layer (bark) that allows woody plants to grow wider instead of just taller

root cortex - structure and function

an outer layer of the root designed for storage and transport

what is the purpose of roots and stem in transport?

water enters the roots via osmosis and root pressure pushes water upward through the plant. Capillary action pulls water upward through the plant stem while cohesion and adhesion keep the water column from collapsing.

What is the purpose of leaves in transport?

leaf does photosynthesis and allows for transpiration which causes cohesion and adhesion to draw water towards the evaporation site.

Cohesion

particles stick to each other

Adhesion

particles stick to another surface

Describe the transportation of sugar in plants

Sugar moves from a source to a sink to even out the concentration of sugar throughout the plant. This means sugar transport can occur in either direction

Source

a cells with high sugar and solute concentrations

sink

a cells with low concentrations, where substances will be sent for storage

Fruit

the thing that the ovary turns into that contains the seed

How do mosses and ferns reproduce?

motile sperm that is water dependent

How do gymnosperms reproduce?

using wind pollenation

Angiosperm reproduction

animal pollination

What regulates plant reproduction

phytohormones which allows seed to go dormant and germinate depending on conditions

What are 3 types of asexual reproduction in plants

cloning, splitting, grafting

Pros and cons of cloning

pros: valuable for agriculture, don’t waste time or energy, shoots and roots can grow into a new plant, spread out quickly in ideal conditions, doesn’t require second parent

cons: lack of variation and diversity, vulnerable to disease and pests, unable to evolve

What is splitting? + pro

splitting a plant into two or more pieces with each piece containing shoots and roots

pro: simple and inexpensive to propagate thin out plants

What is grafting? + pros

a part of the shoot or root is cut and joined to the vascular cambium of another plant

pro: quickens fruit production, helps repair damaged trees, allow combination of characteristics or two varieties of plants

Label the structure of a flower

Sepals - structure and function

Not true leaves at the base of the flower to protect it, photosynthesize and offer structural support

Petals - structure and function

meant to attract pollinators and offer them a landing location and protect the reproductive organs of the flower

Parts of the stamen

3 parts anther, filament and sporangia

anther - structure and function

site of male gametophyte production

Sporangia - function

pollen production site

Parts of the carpels

ovary, stigma, style and sporangia

Ovary - function

where egg lives

Sporangia - function (female)

produces egg

What part of the reproductive system are haploid?

pollen and egg

Monoecious characteristics

plants are both male and female. Can be in the same flower or two different flowers on the same plant

think intersex

Dioecious characteristics

some plants are female and some are male, different gendered flowers occur on different plants

What’s an imperfect/incomplete flower

it lacks petalsWha

What are the 4 pollination mechanisms?

self-pollination, cross-pollination, animal pollination and wind pollination

Self-pollination + cons

plants pollinate themselves or another flower on the same plant. Cons: can lead to loss of genetic variation and species vulnerability

Cross-pollination + pros

plants receive pollen from another plant

pro: increases genetic diversity

Animal-pollination

a form of cross-pollination where insects and other small animals move from plant to plant collecting nectar and moving pollen

Wind-pollination

a form of cross-pollination where a plant mass produces pollen during a short window and wind carries it to other plants

What is germination?

the resumption of growth after dormancy

How does germination occur?

a seed absorbs water and the seed coat breaks. Stored food supports the growth of the embryo before the radicle emerges and becomes the first root. The hypoctyl then emerges to become and early stem.

MONOCOTS VS DICOTS

Gymnosperm characteristics

* vascular plants
* seeds not in fruit
* many adapt to cold climates

Angiosperm characteristics

* Vascular plants
* Seed and fruit bearing
* flowering plant

Monocot characteristics (cotyledon, veins, tissue, roots, pollen, flower)

* One cotyledon
* Parallel veins
* scattered vascular tissue in stem
* circular tissue in root
* fibrous root system
* pollen grain with one opening
* petals in multiples of 3

Dicot characteristics (cotyledon, veins, tissue, roots, pollen, flower)

* two cotyledons
* branching veins
* circular tissue in stem
* Star tissue in root
* pollen grain with 3 openings
* flower petals in multiples of 4 or 5

Vascular vs non vascular plants

vascular:Have xylem and phloem, can grow tall, may not require water for fertilization

non vascular: no xylem or phloem, small in size, require water for fertilization

HUMAN USES (SPACER)

Name + explain 3 human uses for plants

Food + Agriculture: We eat them to get compounds that we don’t naturally produce but require to survive. Also use them to feed animals which we then eat.

Fibers + Textiles: Different plants are used to make or naturally produce materials we can use like cotton, creating papers from fibrous crops and wood chips, etc.

Medicine: Plants produce natural chemical compounds that can be found in up to 25% of prescription medication. Ex. rosy periwinkle contains chemicals that have increased the survival rate of dodging disease.

MOVEMENT AND GROWTH (SPACER)

What is Tropism

a slow change in direction of growth or movement in response to stimulus

Positive tropism

towards light (ie. sunflower)

Negative tropism

away from light (ex. roots)

Phototropism

tropism in response to light

Gravitropism

root always grows downward, shoot always grows upwards

Mastic movement

fast response that is usually reversible (ie. Venus fly trap closing/opening)

Auxins

promotes growth at apical meristem, promotes cell elongation and controls leaf dropping

Gibberellins

Cell enlargement, seed germination, increases fruit size

Cytokinins

cell division and differentiations, delays leaf aging

Ethylene (inhibitor)

promotes fruit ripening

Absicis Acid (Inhibitor)

seed dormancy, closes stomata

Primary Succession

only occurs when there is nothing in an environment (only available resources are sunlight, minerals and water)

Pioneer Species

first species to appear in primary succession ie. moss, lichen, grasses

Secondary succession

occurs when existing ecosystem is disturbed but not completely wiped out and soil (possibly some organisms) are still around

How do humans connect to succession

weeding and herbicides, planting only specific species, putting building in certain locations - contribute to habitat break down